Custom Formatter similar to Text Formatter

I am using Enterprise Library 2.0 released in Jan 2006 to create a custom formatter class. The text formatter provides the facility to create and edit the template on the fly using the enterprise library configuration tool. I would like to implement the
same feature in my custom formatter where I can introduce tokens other than the tokens found in the template editor dialog(timestamp, process name etc). These tokens are business specific (Job Number, Agency Code etc) and sometimes the value for these tokens
are arrived through complex processing inside the custom formatter class. The idea is to use the same formatter but format the logged information in specific formats based upon the system where we are logging the information.

I looked at the "TextFormatter" design and could not find the capability of adding new tokens, so that it appears in the enterprise library configuration tool. Could someone please help me find a solution for this issue? If there is a better way to implement
the same feature, please do let me know.